2012 STU Discussion
Evolving Member
Joined: Mar 2011
Posts: 111
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From: Maryland
With regards to the brake rotor rules, the latest ST rules were prompted specifically by the ultralight rotors GiroDisc made up for me and a few others to use in SP and SM. They are OEM diameter and overall thickness, but the walls and cooling vanes were thinner on the inside to reduce weight. Someone got their panties in a bunch and got them banned for ST because of "safety" reasons. You know - we have to protect the innocent bystanders from the rash of exploding brake rotors that have take so many lives at AX events over the past few year!
/end rant
/end rant
The way I remember it, the lighter rotor proposal got shot down, hence me buying some Girodiscs. If not, time to scrap that off the purchases, but I could have sworn that was off the table.
Joined: Jul 2002
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From: Why do they always call the Evo the Dark Side?
Non-standard brake rotors may be used provided they are of equal
or larger dimensions (diameter and thickness) and made of ferrous
material (e.g. iron). Thickness includes the individual plates of a
vented rotor, as well as the overall dimension. The diameter for re-
placement rotors is measured at the minimum outside dimension.
or larger dimensions (diameter and thickness) and made of ferrous
material (e.g. iron). Thickness includes the individual plates of a
vented rotor, as well as the overall dimension. The diameter for re-
placement rotors is measured at the minimum outside dimension.
I'm not sure whether that means "skinnier than factory rotors when they are worn down to minimum thickness" or "skinnier than factory rotors when brand new" though.
Joined: Jul 2002
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From: Why do they always call the Evo the Dark Side?
OHHHh I think I get it now.
https://www.evolutionm.net/forums/ev...or-review.html
So I guess the key here is
And in the case of those particular Girodiscs, the plates themselves are thinner... meh. Let me break out my electron microscope so I can round to the closest thousandth of a millimeter...
https://www.evolutionm.net/forums/ev...or-review.html
So I guess the key here is
Thickness includes the individual plates of a vented rotor, as well as the overall dimension.
Evolving Member
Joined: Mar 2011
Posts: 111
Likes: 0
From: Maryland
So sounds like I'll be contacting Justin and letting him know that I'm backing out...unless you all promise not to protest me. 
Of course the key here is how do you define the minimal thickness? At the end of its life? At the beginning? Such ridiculous ruling going on these days.
Of course the key here is how do you define the minimal thickness? At the end of its life? At the beginning? Such ridiculous ruling going on these days.
Last edited by piknockout; Jan 24, 2012 at 08:05 AM.
The regular 2-piece GiroDiscs are ok, its the special ultra-light weight ones that wont be legal.
The thinner walled ultra light weight girodiscs where banned almost the same month they came out like a year ago. The latest brake ruling was going to ban any rotor that weighed less than stock (would have to be based off the weight of a new factory rotor). Thankfully that got squashed... Remember you must speak up about these ruling or dumb rules will go through! Even if its a short paragraph for or against, member voices need to be heard!
The thinner walled ultra light weight girodiscs where banned almost the same month they came out like a year ago. The latest brake ruling was going to ban any rotor that weighed less than stock (would have to be based off the weight of a new factory rotor). Thankfully that got squashed... Remember you must speak up about these ruling or dumb rules will go through! Even if its a short paragraph for or against, member voices need to be heard!
Last edited by Autoxevo; Jan 24, 2012 at 03:17 PM.
Joined: Jul 2002
Posts: 1,733
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From: Why do they always call the Evo the Dark Side?
So sounds like I'll be contacting Justin and letting him know that I'm backing out...unless you all promise not to protest me.
Of course the key here is how do you define the minimal thickness? At the end of its life? At the beginning? Such ridiculous ruling going on these days.
Of course the key here is how do you define the minimal thickness? At the end of its life? At the beginning? Such ridiculous ruling going on these days.
Originally Posted by me
When measuring, are you measuring against brand new factory rotors or minimum thickness factory rotors? That's something like 2mm of difference isn't it?
Originally Posted by AWH
Well, a "standard" brake rotor is one that meets the OE specs, which includes service spec since it is still a standard rotor throughout it's service lifetime. So, a "non-standard" rotor which starts closer to the service spec should still be legal, but only until it gets to the service spec min thickness.
From a practical standpoint, there is no difference. You can shave either OE or aftermarket to min service spec and have little service life, or start both near the "new" spec and have plenty. I don't see why there is any confusion.
From a practical standpoint, there is no difference. You can shave either OE or aftermarket to min service spec and have little service life, or start both near the "new" spec and have plenty. I don't see why there is any confusion.
Originally Posted by me
Don't the OE specs only specify overall diameter though, and not individual plate diameter?
Originally Posted by AWH
There are lots of parts on any car that are not listed in commonly available docs. Show me complete specs on a piston or steering knuckle or control arm or even a spring, for example. But clearly there is a blueprint somewhere with specs. In the absence of spec availability, a comparable OE part sourced from the dealership, preferably still bagged, is typically used as a comparable to settle disputes.
The regular 2-piece GiroDiscs are ok, its the special ultra-light weight ones that wont be legal.
The thinner walled ultra light weight girodiscs where banned almost the same month they came out like a year ago. The latest brake ruling was going to ban any rotor that weighed less than stock (would have to be based off the weight of a new factory rotor). Thankfully that got squashed... Remember you must speak up about these ruling or dumb rules will go through! Even if its a short paragraph for or against, member voices need to be heard!
The thinner walled ultra light weight girodiscs where banned almost the same month they came out like a year ago. The latest brake ruling was going to ban any rotor that weighed less than stock (would have to be based off the weight of a new factory rotor). Thankfully that got squashed... Remember you must speak up about these ruling or dumb rules will go through! Even if its a short paragraph for or against, member voices need to be heard!
Evolving Member
Joined: Mar 2011
Posts: 111
Likes: 0
From: Maryland
So sounds like the "regular" Girodisc two piece rotors should be good. I'll talk to Justin to make sure. Then you guys can protest me.
Come at me bro.
On a side note, thanks for the info! Since my new job since Nationals actually requires me to work, my internetz time has been severely reduced. Appreciate it!
Come at me bro.
On a side note, thanks for the info! Since my new job since Nationals actually requires me to work, my internetz time has been severely reduced. Appreciate it!
Last edited by piknockout; Jan 25, 2012 at 12:33 PM.
sounds like you measure each side plate thickness of a brand new factory rotor then subtract the factory service limit all from one side of the rotor (do the same for both sides). that is your minimum rotor side plate thickness. nevermind that if both of them were that thin you'd be under the total thickness limit (for a stock rotor), but the possibility exists that your rotor could only wear on one side and thus the rules can not exclude that. I bet even the ultra light rotors would pass that test.
Last edited by griceiv; Jan 25, 2012 at 02:22 PM.
As much as I wish, I doubt the ultra lites would pass that test. 
Looking at how thin they are, the min thickness of the stockers would never get down to the thickness of the ultra lites. >19 year mechanic.
The pic in post 33 is of the rears, the fronts are much thinner.
Looking at how thin they are, the min thickness of the stockers would never get down to the thickness of the ultra lites. >19 year mechanic.The pic in post 33 is of the rears, the fronts are much thinner.
Joined: Jul 2002
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From: Why do they always call the Evo the Dark Side?
https://www.evolutionm.net/forums/7301390-post34.html
(found this while trying to find weights on all the 2 piece rotors out there)
Joined: Jul 2002
Posts: 1,733
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From: Why do they always call the Evo the Dark Side?
I will be in this year after taking 2011 to run STR (and FP at Nats)... I bought Ranvek's old Evo IX and will probably be making some minor tweaks to it, but for the most part I'll just be driving.
Not sure what Pros and Tours I'll be doing yet... I'm not a huge fan of the schedule and the budget is going to be relatively tight, so it's likely I'll be taking it easy. I'm going to Nats for sure, but it's all the other stuff I don't know about yet.
Not sure what Pros and Tours I'll be doing yet... I'm not a huge fan of the schedule and the budget is going to be relatively tight, so it's likely I'll be taking it easy. I'm going to Nats for sure, but it's all the other stuff I don't know about yet.
2011 = first National Tour win
2012 = hopefully National trophy spot in STU
Mr. 2010 National Champ, what's it going to take for a codrive @ Nationals?
my fat, old tired SSL doesn't want to go, but I do!
Seriously, though, I'm not sure yet. I haven't thought about it much at all. I do know the car is going to need some work before this season, possibly including said ACD pump. The car seems to develop new issues every time I drive it - yesterday it was 3 solid ACD lights. Hopefully it's just a bleed issue.